Where do we get all the carbs we need?

Hi All

I'm very new at this but if you need to maintain 50 to 100 grams a day (Primal Sweet Spot for Effortless Weight Loss), where should they come from. It seems with the meat and veggies I eat everyday, as well as a small amount of fruit, my carbs are not even adding to 50. What am I not eating or eating enough of?

I'm also new and trying to hit 100 carbs a day for maintenance-harder than I thought it would be! I'm adding some things like plantains and bananas, honey, a larabar here and there, and potatoes and rice. Today I managed to hit 106 carbs, but I had pizza for lunch